CN108116168A

CN108116168A - Pneumatic tire

Info

Publication number: CN108116168A
Application number: CN201710777834.7A
Authority: CN
Inventors: 横枕圣二
Original assignee: Toyo Tire and Rubber Co Ltd
Current assignee: Toyo Tire Corp
Priority date: 2016-11-28
Filing date: 2017-09-01
Publication date: 2018-06-05
Anticipated expiration: 2037-09-01
Also published as: US20180147898A1; CN108116168B; JP6742890B2; JP2018086889A

Abstract

Pneumatic tire (10) includes：Carcass ply (18), the carcass ply (18) are rolls-up onto outside (Y2) around bead core (26) from (Y1) on the inside of tire axial；Inner metal enhancement layer (32) and outside metal shielding (34), the inner metal enhancement layer (32) and outside metal shielding (34) are rolls-up onto outside (Y2) in the outside of carcass ply (18) from (Y1) on the inside of tire axial；And buffer layer (36), the buffer layer (36) are arranged between inner metal enhancement layer (32) and outside metal shielding (34) and are rolls-up onto outside (Y2) from (Y1) on the inside of tire axial.Buffer layer (36) includes the hardness rubber higher than the coating rubber of the carcass rubber of composition carcass ply (18), composition inner metal enhancement layer (32) and outside metal shielding (34).

Description

Pneumatic tire

Technical field

The present invention relates to pneumatic tires.

Background technology

Pneumatic tire, particularly heavy duty pneumatic vehicle tire, it is desirable that improve the durability of bead part.In order to improve bead part Durability, effective scheme is：Inhibit the deformation of bead part, carcass ply is made to be reduced in the deformation of turnup end.Then, Japan is special It opens in flat No. 5-155208 and Japanese Unexamined Patent Publication 2008-195339 and proposes a kind of pneumatic tire, the pneumatic tire is in bead core Surrounding is provided with the metal shielding comprising metal cords along on the outside of carcass ply.

In Japanese Unexamined Patent Publication 5-155208 and Japanese Unexamined Patent Publication 2008-195339, in order to improve the reinforcement of bead part effect Fruit, along carcass ply on the outside of be provided with 2 layers of metal shielding.But if around bead core 2 layers of metal is set to add Larger shearing deformation then easily occurs between 2 layers of metal shielding for strong layer.Therefore, stress concentration is strengthened in metal sometimes Layer end and the durability of bead part is caused to deteriorate.

In addition, for bead part, at it between rim flange, larger shearing deformation acts on itself and rim flange phase The position for being referred to as rim belt of contact.2 layers of metal shielding are set around bead core if as discussed above, then tyre bead The rigidity raising in portion, therefore, is difficult to be scattered in entire rim belt, easy office in the shearing deformation that it occurs between rim flange Portion acts on, and rim belt is caused easily to rub rim flange and wear.

The content of the invention

The present invention be in view of the above and implement, it is intended that provide it is a kind of compared with the wear-resisting of rim flange Damage property is not damaged and can make the pneumatic tire that the durability of bead part is improved.

According to the present embodiment, the scheme of following [1]~[8] is provided.

[1] a kind of pneumatic tire, including：Bead core, the bead core are embedded in bead part；Bead filler rubber, the tyre bead External protection cement is configured at the tire radial outside of the bead core；Carcass ply, carcass ply quilt around the bead core Outside is rolls-up onto on the inside of from tire axial；Inner metal enhancement layer, the inner metal enhancement layer is in the outside of the carcass ply Outside is rolls-up onto on the inside of tire axial；Outside metal shielding, the outside metal shielding are strengthened in the inner metal The outside of layer is rolls-up onto outside on the inside of tire axial；And buffer layer, the buffer layer are arranged at the inner metal and strengthen Outside is rolls-up onto between layer and the outside metal shielding and on the inside of tire axial, the carcass ply includes casing ply Cord and the carcass rubber for covering the plies cords, the inner metal enhancement layer and outside metal shielding include metal Cord and the coating rubber for covering the metal cords, the buffer layer include hardness than the carcass rubber and the coating rubber The high rubber of glue.

[2] pneumatic tire according to above-mentioned [1], wherein, the tire axial outboard end of the inner metal enhancement layer, The tire axial outboard end of the tire axial outboard end of the buffer layer and the outside metal shielding is located at than making the tire Side line more leans on the position of tire radial direction foreign side, the inner metal on tyre bead obtained from enclosing the tire radial outer side extension of core The tire axial outboard end of enhancement layer more leans on the position of tire radial direction foreign side positioned at the tire axial outboard end than the buffer layer, The tire axial outboard end of the buffer layer is located at the tire axial outboard end than the outside metal shielding more by tire footpath Position outward.

[3] pneumatic tire according to above-mentioned [1] or [2], wherein, in the tire axial of the inner metal enhancement layer The tire axial inner end of side, the tire axial inner end of the buffer layer and the outside metal shielding is located at than making Side line more leans on the position of tire radial direction foreign side on tyre bead obtained from the tire radial outer side of the bead core extends, described interior The tire axial inner end of side metal shielding is located at the tire axial inner end than the buffer layer more by tire radial direction foreign side Position, the tire axial inner end that the tire axial inner end of the buffer layer is located at than the outside metal shielding is more leaned on The position of tire footpath outward.

[4] pneumatic tire according to above-mentioned [2], wherein, the turnup end of the carcass ply is located at than the inside The tire axial outboard end of metal shielding more leans on the position of tire radial direction foreign side.

[5] pneumatic tire according to above-mentioned [3], wherein, the tire axial inner end of the inner metal enhancement layer The position of tire radial direction foreign side is more leaned on positioned at the turnup end than the carcass ply, the turnup end of the carcass ply is located at than institute The position of tire radial direction foreign side is more leaned in the tire axial inner end for stating outside metal shielding.

[6] pneumatic tire described in any one in above-mentioned [1]~[5], wherein, it is being installed on rim flange Under state, the inner metal enhancement layer, the outside metal shielding and the buffer layer are to clamp the side of the rim belt The entirety of part of the formula with being in contact in the rim flange with rim belt is opposite.

[7] pneumatic tire described in any one in above-mentioned [1]~[6], wherein, the inner metal enhancement layer The metal cords and the outside metal shielding the metal cords for the plies cords each other Inclined in opposite directions.

[8] pneumatic tire according to above-mentioned [7], wherein, the metal cords of the inner metal enhancement layer with The metal cords angulation of the outside metal shielding is 50 °~105 °.

The inner metal enhancement layer in outside and outside metal are rolls-up onto on the inside of tire axial in the outside of carcass ply It is provided between enhancement layer comprising hardness than forming the carcass rubber of carcass ply, forming inner metal enhancement layer and outside metal The buffer layer of the high rubber of coating rubber of enhancement layer, therefore, it is possible to by buffer layer mitigate inside metal shielding with it is outer The shearing deformation occurred between the metal shielding of side can be improved the durability of bead part.Also, with rim flange it Between the shearing deformation that occurs the entirety at the position being in contact with rim flange is readily dispersed in by buffer layer, compared with wheel rim The wear resistance of flange is not easy to reduce.

Description of the drawings

Fig. 1 is the tyre equatorial half section figure for the pneumatic tire for representing first embodiment.

Fig. 2 is the figure for representing the bead part amplification of Fig. 1.

Fig. 3 is to represent the metal cords that the pneumatic tire of Fig. 1, inner metal enhancement layer and outside metal shielding have Compared with the angle of inclination of plies cords and the schematic diagram of inclined direction.

Fig. 4 is the tyre equatorial sectional view for representing the bead part amplification of the pneumatic tire of second embodiment.

Fig. 5 is the tyre equatorial sectional view for representing the bead part amplification of the pneumatic tire of comparative example 1.

Fig. 6 is the tyre equatorial sectional view for representing the bead part amplification of the pneumatic tire of comparative example 2.

Fig. 7 is the tyre equatorial sectional view for representing the bead part amplification of the pneumatic tire of comparative example 3.

Symbol description：

10 ... tires, 12 ... bead parts, 14 ... sidewalls, 16 ... fetus faces, 18 ... carcass plies, 18A ... main parts, 18B ... turnups, 18E ... turnup ends, 19 ... plies cords, 20 ... bandings, 22 ... liners, 24 ... sidewall rubbers, 25 ... wheels Rim band, 26 ... bead cores, 28 ... bead filler rubbers, 32 ... inner metal enhancement layers, 33 ... metal cords, 34 ... outside metals add Strong layer, 35 ... metal cords, 36 ... buffer layers.

Specific embodiment

(first embodiment)

Hereinafter, referring to the drawings, embodiments of the present invention will be described.Fig. 1 is the inflation for representing first embodiment The tyre equatorial sectional view of an example of tire (hereinafter referred to as " tire ") 10, gives the rim flange for being installed on regulation wheel rim Half section in the state of 1.

In this specification, tire axial is the direction parallel with tire rotation axis, identical with tire width direction meaning, figure In, it is represented with symbol Y, on the inside of tire axial and outside is represented respectively with symbol Y1 and Y2.In addition, tire radial direction (Radial Direction it is) direction vertical with tire rotation axis, in figure, is represented with symbols Z, tire radial direction inner side and outside is distinguished It is represented with symbols Z 1 and Z2.

In addition, in this specification, on the outside of the turnup end 18E of carcass ply 18, the tire axial of inner metal enhancement layer 32 Hold 32Eout and tire axial inner end 32Ein, the tire axial outboard end 34Eout of outside metal shielding 34 and tire axis The position of inside side 34Ein, the tire axial outboard end 36Eout of buffer layer 36 and tire axial inner end 36Ein are that will take turns Tire is installed on standard rim and the position uncharged under standard state that the standard internal pressure of filling obtains.So-called standard rim, It is " standard rim " in JATMA specifications, is " Design Rim " in TRA specifications, is " Measuring Rim " in ETRTO specifications. So-called standard internal pressure, is " highest air pressure " in JATMA specifications, is " TIRE LOAD LIMITS AT VARIOUS in TRA specifications " maximum " described in COLD INFLATION PRESSURES " is " INFLATION PRESSURE " in ETRTO specifications.

Tire 10 involved by embodiment includes：Pair of right and left bead part 12, from bead part 12 to tire radial outside It a pair of sidewall portion 14 of extension and is set in a manner that by the footpath of the sidewall controlled 14, end is connected to each other outward together The fetus face 16 being placed between two sidewalls 14.

It is embedded in the inside of tire 10 across the carcass ply 18 extended between a pair of bead portion 12.Carcass ply 18 extend from fetus face 16 through sidewall 14, and both ends are locked in bead part 12.Carcass ply in fetus face 16 18 peripheral side is provided with banding 20.Banding 20 strengthens fetus face 16 in the periphery of carcass ply 18.Carcass ply 18 It is the plies cords arranged with carcass rubber covering along the direction (that is, tire axial Y) being substantially orthogonal with tire circumferential direction F Obtained from 19.As plies cords 19, the metal cords such as all-steel cord or organic fiber cord are used.

It is provided in the inside of carcass ply 18 in the resistance to air permeable rubber layer as the inner peripheral surface for forming tire 10 Lining 22.For sidewall 14, the sidewall rubber 24 for the outside wall surface for forming tire 10 is provided in the outside of carcass ply 18.Separately Outside, it is provided with and is in contact on the outside of the tire axial of bead part 12 with rim flange 1 in the tire radial direction inner side of sidewall rubber 24 Rim belt 25.

As shown in Fig. 2 amplifications, it is embedded in bead part 12 and is stacked winding by the Bead silk for covering rubber and is obtained To collect body composition cricoid bead core 26 and be configured at the bead core 26 tire radial outside Z2 rubber system tire Enclose external protection cement 28.

Carcass ply 18 includes the main part 18A extended since the sidewall 14 and around bead core 26 by from tire Axially inner side Y1 is rolls-up onto the turnup 18B of outside Y2.More specifically, the main part 18A of carcass ply 18 is along bead core 26 and bead filler rubber 28 tire axial medial surface and configure.Also, the tire footpath of main part 18A through bead core 26 is inside Side (downside of Fig. 1 and Fig. 2) Z1 and be rolls-up onto Y2 and turnup 18B on the outside of tire axial and be connected as one.

The turnup 18B of carcass ply 18 matches somebody with somebody along the tire axial lateral surface of bead core 26 and bead filler rubber 28 It puts, front end (i.e., the tire radial outside end of turnup 18B) is turnup end 18E.

2 layers of metal shielding comprising metal cords 33,35 are provided with around carcass ply 18 in bead part 12 (in present embodiment for inner metal enhancement layer 32 and outside metal shielding 34) and be arranged at inner metal enhancement layer 32 and Buffer layer 36 between outside metal shielding 34.

Inner metal enhancement layer 32 is formed by covering coating rubber to the metal cords such as all-steel cord 33.Inside Metal shielding 32 the outside of carcass ply 18 by the inside of tire axial Y1 be rolls-up onto outside Y2, in the week of bead core 26 The mode for enclosing the outside of covering carcass ply 18 is overlapped in carcass ply 18.

Outside metal shielding 34 is formed by covering coating rubber to the metal cords such as all-steel cord 35.Outside Metal shielding 34 the outside of buffer layer 36 by the inside of tire axial Y1 be rolls-up onto outside Y2, with around bead core 26 The mode for covering the outside of buffer layer 36 is overlapped in buffer layer 36.

In addition, in the example, form the metal cords 35 of outside metal shielding 34 and be coated rubber by with forming inside gold Belong to the metal cords 33 of enhancement layer 32 and be coated the same material of rubber phase and formed, it is however also possible to strengthen with forming inner metal The metal cords 33 and coating rubber of layer 32 are different.

Buffer layer 36 the outside of inside metal shielding 32 by the inside of tire axial Y1 be rolls-up onto outside Y2, in tire The mode in the outside for covering inner metal enhancement layer 32 around circle core 26 is overlapped in inner metal enhancement layer 32.

The rubber for forming buffer layer 36 and the carcass rubber for forming carcass ply 18, the quilt of composition inner metal enhancement layer 32 Rubber, the coating rubber phase ratio for forming outside metal shielding 34 are covered, the rubber hardness after vulcanization is larger.In present embodiment, The rubber hardness of carcass rubber and the coating rubber of composition inner metal enhancement layer 32 and outside metal shielding 34 is set as 75, The rubber hardness for forming the rubber of buffer layer 36 is set as 85.Certainly, the present invention is not limited thereto, if enumerating an example, carcass The rubber hardness of the coating rubber of rubber and composition inner metal enhancement layer 32 and outside metal shielding 34 can be for example 70 ~79.The rubber hardness for forming the rubber of buffer layer 36 for example can be 80~90.

Herein, rubber hardness is according to JIS K6253, is measured obtained value in terms of A type hardness testers under 23 DEG C of atmosphere (firmly Degree meter hardness).

The method for assigning such a difference of hardness is not particularly limited.It for example, can be by changing the rubber constituent used Species, increase carbon black, the fillers such as silica amount or increase vulcanizing agent, the amount of vulcanization accelerator improves rubber Hardness.

Inner metal enhancement layer 32, outside metal shielding 34 and buffer layer 36, positioned at than (or the tyre bead of bead core 26 External protection cement 28) more by the axially external Y2 of tire position front end (hereinafter referred to as tire axial outboard end) 32Eout, 34Eout, 36Eout is located at than side line L1 on tyre bead obtained from making the tire radial outer side 26a extensions of bead core 26 more by tire radial direction The position of foreign side Z2.As a result, in a state that tire 10 is installed on rim flange 1, inner metal enhancement layer 32, outside metal Enhancement layer 34 and buffer layer 36 are whole with the part that is in contact in rim flange 1 with rim belt 25 in a manner of clamping rim belt 25 Body is opposite.

The tire axial outboard end 32Eout of inner metal enhancement layer 32 is located at the tire axis than outside metal shielding 34 Outside side 34Eout, the tire axial outboard end 36Eout of buffer layer 36 more lean on the position of tire radial direction foreign side Z2, and are located at Turnup end 18E than carcass ply 18 more leans on the position of tire radial direction inner side Z1.The tire axial outboard end of buffer layer 36 36Eout is located at the tire axial outboard end 34Eout than outside metal shielding 34 more by the position of tire radial direction foreign side Z2.

Tire axial outboard end 32Eout, 34Eout, 36Eout of each layer are configured to stagger on tire radial direction Z as a result, So as to the tire axis of the turnup end 18E of carcass ply 18, inner metal enhancement layer 32 is followed successively by since the tire radial outside Z2 Outside side 32Eout, the tire axial outboard end 36Eout of buffer layer 36, the tire axial outside of outside metal shielding 34 Hold 34Eout.

In addition, in inner metal enhancement layer 32, outside metal shielding 34 and buffer layer 36 be located at than bead core 26 (or Bead filler rubber 28) more by tire axially inner side Y1 position front end (hereinafter referred to as tire axial inner end) 32Ein, 34Ein, 36Ein are located at than side line L2 more rollers under tyre bead obtained from making the tire radial direction inner side face 26b extensions of bead core 26 The position of tire footpath Z2 outward.Tire axial inner end 32Ein, 36Ein of inner metal enhancement layer 32 and buffer layer 36 are located at The position of tire radial direction foreign side Z1 is more leaned on than side line L1 on tyre bead.

Herein, with reference to Fig. 1, carcass ply 18, inner metal enhancement layer 32, outside metal shielding 34 and buffering are enumerated An example of the end position of layer 36, can be by the tire radial direction Z from nominal diameter Rn until the turnup end 18E of carcass ply 18 On length H0 be set as 38mm, be by the tire axial inner end 32Ein from nominal diameter Rn to inner metal enhancement layer 32 The length H1in on tire radial direction Z only is set as 45mm, by the tire axis from nominal diameter Rn to inner metal enhancement layer 32 The length H1out on tire radial direction Z until outside side 32Eout is set as 30mm, will be from nominal diameter Rn to outside metal The length H2in on tire radial direction Z until the tire axial inner end 34Ein of enhancement layer 34 is set as 5mm, will be straight from nominal Length H2out settings of the footpath Rn on the tire radial direction Z until the tire axial outboard end 34Eout of outside metal shielding 34 For 20mm, by the length from nominal diameter Rn on tire radial direction Z until the tire axial inner end 36Ein of buffer layer 36 H3in is set as 15mm, by the tire radial direction Z from nominal diameter Rn until the tire axial outboard end 36Eout of buffer layer 36 On length H3out be set as 25mm.

The angle of inclination for the metal cords 33,35 that inner metal enhancement layer 32 and outside metal shielding 34 have and inclination Direction is set as follows.

Fig. 3 is provided, and carcass ply 18, inner metal enhancement layer 32, the outside metal shielding 34 in bead part 12 are unfolded In the state of, angle of inclination that metal cords 33,35 are compared with the plies cords 19 of carcass ply 18 and inclined direction.

As shown in figure 3, the metal cords 33 of inner metal enhancement layer 32 and the metal cords 35 of outside metal shielding 34 For the plies cords 19 of carcass ply 18, inclined in opposite directions is intersected each other.In present embodiment, inside gold Belong to the angle [alpha] that the metal cords 33 of enhancement layer 32 have+25 ° for the plies cords 19 of carcass ply 18.Outside The metal cords 35 of metal shielding 34 have -55 ° of angle beta for the plies cords 19 of carcass ply 18.When So, the present invention is not limited thereto.The metal cords 33 of inner metal enhancement layer 32 compared with carcass ply 18 plies cords It can be set as+15 °~+35 ° of angle [alpha] for 19.The metal cords 35 of outside metal shielding 34 are compared with carcass ply It can be set as -40 °~-70 ° of angle beta for 18 plies cords 19.In addition, the metal of inner metal enhancement layer 32 Cord 33 and the intersecting angle of the metal cords 35 of outside metal shielding 34 are preferably close to right angle, metal cords 33 and metal The intersecting angle of cord 35 is preferably 50~105 ° of scope.

In addition, in present embodiment, the metal cords 33 of inner metal enhancement layer 32 compared with carcass ply 18 cord There is+15 °~+35 ° of angle for layer cord 19, but can also be by inner metal enhancement layer 32 and outside metal shielding 34 come compared with the angle exchange of plies cords 19.I.e., it is possible to the angle [alpha] for making inner metal enhancement layer 32 is -40 ° The angle beta of~-70 ° and outside metal shielding 34 is+15 °~+35 °.

In above present embodiment, it is provided with and includes between inside metal shielding 32 and outside metal shielding 34 Rubber hardness after the vulcanization high rigidity bigger than the coating rubber for forming inner metal enhancement layer 32 and outside metal shielding 34 The buffer layer 36 of rubber.Therefore, it is possible to reduce inner metal enhancement layer 32 and outside metal shielding 34 by buffer layer 36 Between the shearing deformation that occurs, so as to inhibit stress concentration in the end of inner metal enhancement layer 32 and outside metal shielding 34 Portion can be improved the durability of bead part.

Also, the shearing deformation occurred when driving between rim flange 1 and rim belt 25 easily by buffer layer 36 and Entire rim belt is scattered in, rim belt 25 can be inhibited and worn.

In addition, in present embodiment, tire axial outboard end 32Eout, the wheel of buffer layer 36 of inner metal enhancement layer 32 The tire axial outboard end 34Eout of the axially external end 36Eout of tire and outside metal shielding 34 is located at the tire than bead core 26 Side line L1 more leans on the position of tire radial direction foreign side on circle.That is, in a state that tire 10 is installed on rim flange 1, inside Metal shielding 32, outside metal shielding 34 and buffer layer 36 in a manner of clamping rim belt 25 with rim flange 1 in wheel The entirety for the part that rim band 25 is in contact is opposite.Therefore, it is possible to which the inner metal enhancement layer 32 of buffer layer 36 and outer will be accompanied Side metal shielding 34 is arranged at the entirety at the position for being in contact and being easily stressed with rim flange 1, can effectively drop The shearing deformation occurred between low inner metal enhancement layer 32 and outside metal shielding 34, also, inhibit rim belt 25 and wear.

In addition, in present embodiment, outside the turnup end 18E of carcass ply 18, the tire axial of inner metal enhancement layer 32 Side 32Eout, the tire axial outboard end 36Eout of buffer layer 36, the tire axial outboard end of outside metal shielding 34 34Eout is configured to stagger on tire radial direction Z.Therefore, it is possible to make by carcass ply 18, inner metal enhancement layer 32 and outside Stiffening effect caused by metal shielding 34 more periodically reduces closer to tire radial outside Z2, and can inhibit deformation should Power is concentrated on the outside of the tire axial of bead part 12, is improved durability.

(second embodiment)

Next, based on Fig. 4, second embodiment of the present invention is illustrated.It should be illustrated that for implementing with first The identical part of mode omits the description, and different parts is illustrated.

In present embodiment, it is arranged at the tire axial inner end 34Ein's of the outside metal shielding 34 of bead part 12 Position is different from above-mentioned first embodiment.

Specifically, inner metal enhancement layer 32, outside metal shielding 34 and buffer layer 36, tire axial inner end 32Ein, 34Ein, 36Ein are located at the position that tire radial direction foreign side Z2 is more depended on than side line L1 on tyre bead.

The tire axial inner end 32Ein of inner metal enhancement layer 32 is located at turnup end 18E than carcass ply 18, outside The tire axial inner end 34Ein of metal shielding 34, the tire axial inner end 36Ein of buffer layer 36 are more radially outer by tire The position of square Z2.The tire axial inner end 36Ein of buffer layer 36 is located on the inside of the tire axial than outside metal shielding 34 34Ein is held more to lean on the position of tire radial direction foreign side Z2.

Inner metal enhancement layer 32, outside metal shielding 34 and buffer layer 36 are configured to the wheel of bead core 26 as a result, In tire radial inside portion is wrapped in, also, tire axial inner end 32Ein, 34Ein, 36Ein of each layer are configured in tire Stagger on radial direction Z, so as to be followed successively by the tire axial inner end of inner metal enhancement layer 32 since the tire radial outside Z2 32Ein, the turnup end 18E of carcass ply 18, the tire axial inner end 36Ein of buffer layer 36, outside metal shielding 34 Tire axial inner end 34Ein.

In above present embodiment, except inner metal enhancement layer 32, outside metal shielding 34 and buffer layer 36 Beyond tire axial outboard end 32Eout, 34Eout, 36Eout, inner metal enhancement layer 32, outside metal shielding 34 and slow Tire axial inner end 32Ein, 34Ein, the 36Ein for rushing layer 36 also are located at more depending on tire radial direction foreign side Z2 than side line L1 on tyre bead Position, inner metal enhancement layer 32, outside metal shielding 34 and buffer layer 36 are configured to：By the tire footpath of bead core 26 Inwardly including portion envelops.Therefore, it is possible to improve as caused by inner metal enhancement layer 32 and outside metal shielding 34 Stiffening effect can be improved the durability of bead part.

In addition, in present embodiment, tire axial inner end 32Ein, the wheel of buffer layer 36 of inner metal enhancement layer 32 Tire axially inner side end 36Ein, the tire axial inner end 34Ein of outside metal shielding 34 are configured on tire radial direction Z wrong It opens.Therefore, it is possible to make as caused by inner metal enhancement layer 32 and outside metal shielding 34 stiffening effect closer to tire Radial outside Z2 more periodically reduces, and can inhibit deformational stress and concentrate on the inside of the tire axial of bead part 12, make durable Property is improved.

In addition, other compositions and effect are identical with first embodiment, detailed description will be omitted.

(other embodiment)

In above-mentioned first embodiment and second embodiment, to being arranged at inner metal enhancement layer 32 and outside metal Buffer layer 36 between enhancement layer 34 is only by the rubber hardness after vulcanizing than forming the carcass rubber of carcass ply 18, forming inside The situation that the big rubber of the coating rubber of metal shielding 32 and outside metal shielding 34 is formed is illustrated, but, Can be by the general nylon fiber (aliphatic polyamide fiber) representated by nylon66 fiber, nylon 6 etc. with hardness than carcass rubber, Form the layer obtained from being coated the high rubber covering of rubber of inner metal enhancement layer 32 and outside metal shielding 34.

More than, embodiments of the present invention are illustrated, still, which proposes as an example, and It is not intended to limit the scope of invention.The new embodiment can be implemented with other various forms, can not depart from hair Various omissions, displacement, change are carried out in the range of bright purport.

【Embodiment】

In order to specifically provide the composition of the above embodiment and effect, the inflated wheel that trial-production tire size is 11R22.5 Tire carries out performance evaluation.Evaluation method is as follows.

(1) bead durability is tested

Under conditions of air pressure 850kPa, load 29.4kN, speed 50km/h, make rolling of the test tire in diameter 1700mm Traveling is until break down on cylinder.The operating range for making comparative example 1 is 100, is recorded with index.Numerical value is bigger, the better.

(2) abrasion test of wheel rim contact portion

Under conditions of air pressure 850kPa, load 29.4kN, make 50,000 km of test tire running, measure the wheel of rim belt 25 The thickness of rim contact portion.Thickness before traveling starts is 4mm.For numerical value closer to 4mm, abrasion is fewer, the better.

The trial-production tire for carrying out performance evaluation is as follows.In addition, respectively manufacture experimently tire, composition carcass ply 18, inner metal The rubber hardness of the rubber material of enhancement layer 32, outside metal shielding 34 and buffer layer 36, from nominal diameter to carcass ply 18th, the length until the end of inner metal enhancement layer 32, outside metal shielding 34 and buffer layer 36 is as shown in table 1.

1 ＞ of ＜ embodiments

Embodiment 1 is the tire formed with Fig. 1 involved by first embodiment and bead part shown in Fig. 2.

2 ＞ of ＜ embodiments

Embodiment 2 is the tire formed with the bead part shown in Fig. 4 involved by second embodiment.From nominal diameter The length H2in of tire radially and embodiment 1 until the tire axial inner end 34Ein of outside metal shielding 34 Difference, it is in addition, same as Example 1.

1 ＞ of ＜ comparative examples

Comparative example 1 is the tire shown in Fig. 5, although to cover the side in the outside of carcass ply 18 around bead core 26 Formula has overlapped inner metal enhancement layer 32, but is not provided with outside metal shielding 34 and buffer layer 36.In addition, It is same as Example 1.

2 ＞ of ＜ comparative examples

Comparative example 2 is the tire shown in Fig. 6, although to cover the side in the outside of carcass ply 18 around bead core 26 Formula has overlapped inner metal enhancement layer 32, but is not provided with outside metal shielding 34 and buffer layer 36.Comparative example 2 In, the coating rubber covering of nylon fiber cord is obtained by being provided in a manner of covering the outside of inner metal enhancement layer 32 The first nylon enhancement layer 50, along the tire axial of the first nylon enhancement layer 50 on the inside of Y1 be provided with and use nylon fiber cord Second nylon enhancement layer 52 obtained from being coated rubber covering.In addition, it is same as Example 1.

3 ＞ of ＜ comparative examples

Comparative example 3 is tire shown in Fig. 7, although to cover the side in the outside of carcass ply 18 around bead core 26 Formula has overlapped inner metal enhancement layer 32, to be provided with outside metal in a manner of covering the outside of inner metal enhancement layer 32 Enhancement layer 34, but buffer layer 36 is not present between inside metal shielding 32 and outside metal shielding 34.In addition, It is same as Example 1.

【Table 1】

The results are shown in Table 1.It is added with comparative example 1, in comparative example 1 and is provided with nylon enhancement layer 50,52 or outside gold The comparative example 2,3 for belonging to enhancement layer 34 is compared, and buffering is provided between inside metal shielding 32 and outside metal shielding 34 In the embodiment 1 and 2 of layer 36, the abrasion resistance properties of bead durability and wheel rim contact portion are greatly improved.By outside gold The tire axial inner end 34Ein for belonging to enhancement layer 34 is configured at than side line L1 on tyre bead more by the position of tire radial direction foreign side Z2 In embodiment 2, compared with Example 1, bead durability is better.

Claims

1. a kind of pneumatic tire, including：

Bead core, the bead core are embedded in bead part；Bead filler rubber, the bead filler rubber are configured at the tire of the bead core Radial outside；Carcass ply, the carcass ply are rolls-up onto outside around the bead core on the inside of tire axial；Inside Metal shielding, the inner metal enhancement layer are rolls-up onto outside in the outside of the carcass ply on the inside of tire axial；Outside Side metal shielding, the outside metal shielding are rolls-up onto in the outside of the inner metal enhancement layer on the inside of tire axial Outside；And buffer layer, the buffer layer be arranged between the inner metal enhancement layer and the outside metal shielding and by Outside is rolls-up onto on the inside of from tire axial,

The carcass ply includes plies cords and covers the carcass rubber of the plies cords, and the inner metal is strengthened Layer and outside metal shielding include metal cords and cover the coating rubber of the metal cords, and the buffer layer includes hardness The rubber higher than the carcass rubber and the coating rubber.

2. pneumatic tire according to claim 1, wherein,

The tire axial outboard end of the inner metal enhancement layer, the tire axial outboard end of the buffer layer and the outside The tire axial outboard end of metal shielding is located at than tyre bead obtained from making the tire radial outer side extension of the bead core Upper side line more leans on the position of tire radial direction foreign side,

The tire axial outboard end of the inner metal enhancement layer is located at the tire axial outboard end more roller than the buffer layer The position of tire footpath outward, the tire axial outboard end of the buffer layer are located at the tire axial than the outside metal shielding Outboard end more leans on the position of tire radial direction foreign side.

3. pneumatic tire according to claim 1 or 2, wherein,

The tire axial inner end of the inner metal enhancement layer, the tire axial inner end of the buffer layer and the outside The tire axial inner end of metal shielding is located at than tyre bead obtained from making the tire radial outer side extension of the bead core Upper side line more leans on the position of tire radial direction foreign side,

The tire axial inner end of the inner metal enhancement layer is located at the tire axial inner end more roller than the buffer layer The position of tire footpath outward, the tire axial inner end of the buffer layer are located at the tire axial than the outside metal shielding The position of tire radial direction foreign side is more leaned in inner end.

4. pneumatic tire according to claim 2, wherein,

The turnup end of the carcass ply is located at the tire axial outboard end than the inner metal enhancement layer more by tire radial direction The position of foreign side.

5. pneumatic tire according to claim 3, wherein,

The tire axial inner end of the inner metal enhancement layer is located at the turnup end than the carcass ply more by tire radial direction The position of foreign side,

The turnup end of the carcass ply is located at the tire axial inner end than the outside metal shielding more by tire radial direction The position of foreign side.

6. pneumatic tire according to claim 1, wherein,

In the state of rim flange is installed on, the inner metal enhancement layer, the outside metal shielding and the buffering The entirety of part of the layer in a manner of clamping the rim belt with being in contact in the rim flange with rim belt is opposite.

7. pneumatic tire according to claim 1, wherein,

The metal cords of the metal cords of the inner metal enhancement layer and the outside metal shielding compared with Inclined in opposite directions each other for the plies cords.

8. pneumatic tire according to claim 7, wherein,

Formed by the metal cords of the metal cords of the inner metal enhancement layer and the outside metal shielding Angle is 50 °~105 °.